Search

This paper presents the results of the investigations of volcanic rocks of Middle Miocene age in the central parts of the Varadar zone for the first time. The volcanic rocks that appear in the Čitakliјa locality, according to their petrological and mineralogical characteristics, represent basic igneous rocks and they are transitional rocks between phonotephrites and high potassium shoshonites. The geochemical distribution of trace elements and elements from the group of rare earths (REE), as well as isotopes of 87Sr/86Sr (0.708348) and isotope values of 143Nd/144Nd (0.512319) indicate the fact that the magmatic sources of these rocks can be located in the border region between the upper mantle and the lower part of the continental crust.

Crystalline stibnite occurrences in the Republic of Macedonia in several antimony deposits such as Allchar, Lojane and Krstov dol. The best stibnite crystals can be found in the central parts of the Allchar mine. Crystals of stibnite are thick to thin elongated prisms with vertical striations, lead gray color and high metallic lusters. Stibnite also occurs in columnar, granular, blended and compact habits. Cleavage is perfect on {010} and imperfect on {100},{110}. The density determined by pycnometer is 4.62 g/cm3 . Hardness is 2. The concentration of the oxides is: Sb:70,912-71,155%, S:27,166-28,166%. The following trace elements were also detected: As, Tl, V, Se, Ba, Ag, Cr, W, P. The unit cell parameters obtained using the main reflection lines of X-ray diffraction are: a = 11.24 Å, b = 3.84 Å, c = 11.34 Å, V = 490.43 Å3 , Z: 4.

Late Miocene volcanism in the Tikveš Valley (MRZEN locality) is characterized by the occurrence of volcanic rocks and it is the beginning of volcanic activity in the southern parts of the Republic of North Macedonia; It occurs on the transverse tectonic structures with E-W direction that are a consequence of the extension that occurred in this region in the period of about 10 Ma (in the region of Mrzen 8.32 Ma) and which is a direct consequence of the subduction processes in the Aegean region. The chemical and geochemical characteristics of volcanic rocks indicate that these are rocks that have an intermediate character, but also contain olivine as phenocrysts, so based on that could be defined as alkaline basalts. The PEE content as well as the strontium isotopes ( 87Sr/86Sr) content range in the interval 0.706671–0.706795, while the neodymium isotopes 143Nd/144Nd range in the interval 0.512441–0.512472. Strontium isotopes (87Sr/86Sr) clearly indicate the origin of the primary magma from which these volcanic rocks differentiated. The source of the magma is unambiguously in the upper layer and therefore these rocks differ from the Pliocene volcanism on Kožuf Mountain where the strontium isotopes are in the range 0.7080-0.7090.

One of the most interesting aspects of Crn Kamen mineralogy is the presence of several oxide phases, some of which are extremely rare in nature. The first mentioned oxide found on this locality, apart from quartz, is davidite Ce(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38 which was described by Damjanović and Vukasović, (1961). Fragments of former larger crystals estimated up to 15 cm in size were found in a cavity of the crushed and weathered syenites. Bermanec et al., (1990) analyzed the samples of the same crystal samples and determined that it is actually a uranium rich metamictic senaite Pb(Mn,Y,U)(Fe,Zn)2(Ti,Fe,Cr,V)18(O,OH)38. However, even that was not the correct determination. Wülser et al., (2005) found a mineral of a similar, uranium rich composition in the western Swiss Alps which was not metamictic. This enabled them to see that the uranium is a species defining cation and they named the new mineral cleusonite (Pb,Sr)(U4+,U6+)(Fe2+,Zn)2(Ti,Fe2+,Fe3+)18(O,OH)38. It was mentioned that the samples from Crn Kamen also correspond to metamictic cleusonite, not senaite or davidite (Wülser et al., 2005; Biagioni et al., 2014). Brannerite UTi2O6 was also found in the silicified parts of the fine-grained Quartz syenits in the direction of Topolčane (Vukasović and Mihajlović-Vlaić 1963). In addition to these rare phases, large rutile crystals as well as hematite, ilmenite and magnetite can be found (Barić, 1965). Possibly the most peculiar aspect of the Crn Kamen mineralogy is the mineral macedonite PbTiO3 which was first described here as well (Radusinović and Markov, 1971).

Late Miocene volcanism in the Tikves valley (locality MRZEN locality) is characterized by the appearance of volcanic rocks that also mark the beginning of volcanic activity in the southern parts of the Republic of North Macedonia. This volcanism appears on the transversal tectonic structures with E�W extension that are a consequence of the extension occurring in this region in the period of about 10 MA (in the area of Mrzen, 8.32 MA) and which is a direct consequence of the subduction processes in the Aegean region. Detailed microscopic examinations of 5 samples of volcanic rocks show that they have a typical porphyritic structure, while the texture is trachytic. Phenocrysts that have idiomorphic forms are represented by: olivine, clinopyroxene, orthopyroxene, plagioclase and magnetite. In some places there are alterations of phenocrysts to: iddingsite (mixture of smectite-chlorite-goethite), clay and/or zeolites, and calcite. The ground mass is hypocrystalline and in places it is vitreous. The chemical and geochemical characteristics of volcanic rocks indicate that they are rocks with an intermediate character, but in the modal composition of the rock olivine as phenocrystals appears, and, based on this, these rocks could be defined as alkaline basalts. The content of strontium isotopes 87Sr/86Sr ranges in the interval of 0.706671-0.706795, while neodymium isotopes 143Nd/144Nd it ranges in the interval of 0.512441-0.512472. Strontium isotopes (87Sr/86Sr) clearly indicate the origin of the primary magma from which these volcanic rocks differentiated. The source of the magma is unambiguously in the upper mantle and therefore these rocks differ from the Pliocene volcanism of Kozuf Mountain where strontium isotopes are in the interval of 0.7080-0.7090 and the source of the magmas is located in the upper part of the border area of the upper mantle and the lower parts of the continental crust

Arsenic polluted groundwater was found in the Strumica region located in the south-east part of the Republic of North Macedonia where an intensive agriculture production is concentrated. Out of 185 samples collected from boreholes, 64 samples have arsenic in concentrations greater than 10 µg/L, from which 30 samples have a concentration greater than 50 µg/L with a maximum concentration of 176.56 µg/L. Pollution mostly occurs in the groundwater located in the central part of the valley characterized by alluvial plains and young aquifer. Around 57% of the polluted samples have origin from groundwater with a depth greater than 40 m. Reductive environment, high Fe, Mn, HCO3- concentrations as well as low SO42- and NO3- content in polluted samples suggests that reductive dissolution is a major mechanism by which arsenic is released into the groundwater. Highly polluted samples are characterized by high concentrations of Mn and Fe. Other investigated ions are present in low concentrations. Single factorial ANOVA showed significant differences between As concentrations in shallow and deep groundwater. Multivariate factor analysis was performed to identify the covariance structure between the investigated variables. Arsenic was positively correlated to HCO3- and Mn in groundwater with depth lower than 40 m and with HCO3-, Ca, and Mn in groundwater with depth greater than 40 m suggesting that arsenic is mobilized in groundwater by reductive dissolution of Mn oxides from the bedrock.

The present Access database for the Cukar 2 East ore body as one of the constitutional parts of the Buchim ore deposit was developed as an integral part of the mega-European project ProMine, which aimed to define the data processing and their presentation in the Pan-European GIS database for primary ore deposits and anthropogenic mineral resources. The implementation of this project aimed at forecasting and estimating the mineral resources at the Pan-European level, thus constituting a modern overview of European metallurgy. For successful completion of work package 1 within the ProMine project, databases for primary and secondary mineral resources (ProMine-MD) and anthropogenic concentrations (ProMine-AC) have been created. Our Access Database that we created (in Microsoft Access) is an integral part of the large ProMine-MD database, which covers 34 European countries and has about 12,979 records for mines, ore deposits and ore occurrences. The Cukar 2 East ore body database, is a preliminary effort to compile geological surveys and their data for this ore body into an understandable database that will be available to interested parties. The organization of databases for other metal deposits in the Republic of Northern Macedonia and the experiences gained, enabled us to construct a respectable database for the ore body Cukar 2 East, Buchim mine. Our paper explains the steps we took to create the Microsoft Access database using the representative and available data for the Cukar 2 East ore body. The database in question is constructed with the most important data that refer especially to the geological, metallogenetic and economic parameters of this ore body. Particular attention should be paid to the main economic parameters that are an integral part of this database. Namely, it is an ore body with active mining (Solway company) with proven reserves of 27,161 Mt ore where the content of copper is 0.206% Cu and gold with 0.165 g / t Au. In the part of the mineralization and the surrounding rocks, we entered reliable data that clarify the age of the mineralization (16.4-13.6 Ma relative 16 Ma absolute) while the age of the rock in which the mineralization is located was determined as relative one between 28.4 - 23, 03 Ma while the absolute method (K/Ar) showed 27 Ma. From a petrological point of view we want to emphasize that the geological setting is composed of rocks with composition: gneiss, andesite and latite. From an economic point of view, it is important to emphasize that proven mineral reserves of 27,161 Mt (from 2017) give serious economic expectations from copper metal potential of 55 952 t and gold of 448 kg Au. The database in question also provides additional information in support of the positive economic effects expected with the exploitation of the ore from the телоukar 2 East ore body.

In recent years, high air pollution episodes in most of North Macedonia's cities have dominated the headlines, confirming popular view that dirty air is by far the most serious environmental and health issue confronting the country's urban population. The country's capital and most populous city Skopje is frequently at the top of numerous pollution rankings and is among the cities in Eastern Europe and Central Asia that significantly exceed the EU yearly limit value for PM 2.5. (Almeida et al 2020). However, the restricted scope and temporally scattered data about pollution sources, allow for scepticism, thwarting any efforts to apply effective abatement techniques. Main goal of Source Apportionment (SA) study for Skopje Agglomeration was to derive information about pollution sources and the amount they contribute to ambient air pollution levels. The study includes selection of representative receptor/monitoring site, sampling, chemical speciation, and construction of multivariate receptor model, following the European Guide on Air Pollution Source Apportionment with Receptor Models, Revised version, JRC (2019). Karposh urban background monitoring station, a part of national monitoring network, was selected as representative receptor exposed to the mix of sources in the urban area.

The present study was performed to describe an occurrence of very big crystals of brucite and its associated minerals in locality of 'Ržanovo. It was also intended to describe the conditions of crystallization of such a big crystal. Within highly altered peridotite host rock in ‘Ržanovo region, acicular, up to 80 cm in size, colorless crystals of brucite were found. It has been also found as small, and in some places large lenses filled with acicular brucite. Crystals were found in serpentinized ultrabasic rocks, within veins. Needles are perpendicular to vein walls. Chemical composition is determinated with ICP-MS. MgO (66.39–69.13), Al2O3 (0.343–0.601), FeO (1.956–4.025), MnO2 (0.239–0.360), TiO2 (0.003–0.009), LOI (25.1–27.4). Its unit cell is: a = 3.1458 (7), c = 4.766 (2) Å (rhombo-hedral a = 2,4130 Å, α = 81.36°), V = 40.84 (2) Å3, Z = 1.

This paper presents the latest studies on petrographic composition and chemical and geochemical characteristics of metamorphic (alkaline gneisses) and igneous rocks (alkaline syenites) from the locality of Alinci, as well as research related to the age of pegmatitе occurrences in the locality Alinci, with the application of the K/Ar method on the mineral microcline. In terms of the occurrence of minerals, Alinci is a highly exotic locality, with the occurrence of numerous minerals (quartz, albite, microcline, arfvedsonite, augite, titanite, zircon, apatite, magnetite, davidite, macedonite and others). The age of the Alinci pegmatites is determined as the Cretaceous period, and the formation of the pegmatites is the consequence of the partial melting of gneisses and the formation of alkaline syenites during the metamorphic and tectono-magmatic processes, which took place within the Pelagonian metamorphic complex.

This paper presents the research that has been done on the determination of the chemical composition of silver tetradrachms (museum specimens) using the SEM-EDS method. Studies have shown that the chemical composition (Ag, Cl, Fe, Pb) of the tetradrachms from the Isar-Marvinci site is similar to those from Aegean, Pella and Amphipolis. It can be concluded that these are coins that have a very homogeneous chemical composition (Ag; 96.7-98.3 %; Cl; 1.01-1.59 % ; Fe; 0.11-0.31 %; Pb; 0.31-0.58%; Au; 0.16-1.10%)

The paper presents the results of the tests on the chemical composition of coins from the Pelagonia region (North Macedonia) dating from Roman times, using the SEM-EDS method. From the results obtained, it can be concluded that there are two types of coins present: bronze and copper. In the case of bronze coins based on the chemical composition of bronze, two types of coins can be distinguished: 1) bronze coins with the following composition: Cu�45,81-46,31 %; Sn- 26,78-47,26%; Pb-6,37-9,37 %. In their composition these bronze coins are not similar to the bronze coins from other regions of the world. 2) bronze coins with the following composition: Cu-65-85 %; Sn-12-31 %; Pb-3,49-11,59 %. The composition of bronze of these coins is similar to that from Egypt, Ancient Greece, Phoenicia, Ceylon, Korea and the Celtic bronze coins in England. 3) copper coins with the following composition: Cu-97,53-98,12 %, Pb-1,11-1,50 %. The composition of these copper coins is very similar to the composition of coins from Mycenae and Thebes

Regarding the problem of the age the Pelagon, two questions can be asked: the first question is the age of the metamorphic rocks (??) and the second one is the age of the consolidation of the massif (?). The metamorphic complex of the Pelagon is polymetamorphic and polydeformational, and the age of the oldest relics has not been deter�mined yet. This information paper for the first time presents information about determining the age of metamorphic rocks using the U / Pb method of samples representing titanites from the lower metamorphic complex (gneisses). The information obtained indicates an age in the range of about (1840 ±25 m / y. This is the first information that has been received and, in any case, it should be rechecked in some further research. The second question concerning the age of the consolidation of massifs has been documented in more detail in almost all crystalline massifs on the Balkans and that age ranges from about 550 to 600 million years, and this consolidation ends with an intense granitic (Herzinian) magmatism of about 300 million years of age.

Shock quartz (shock metamorphic quartz) occurs in the processes of shock metamorphism or impact metamorphism. Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is gener�ally discounted due to the lack of metamorphic effects unequivocally associated with explosions and the difficulty in reaching sufficient pressures during such an event. The paper presents the results of examinations on a sample from the archaeological locality Stobi and they indicate that it is a shock quartz, occurrence of spherical shapes in the sample.

The Dren-Bohula massif covers the western parts of the ophiolite complex Demir Kapija Gevgelija and geologically it does not represent a separate tectonic segment. It is built of the following rocks: verlite, troctolite, olivine gabbro, gabbro, Uralite gabbro, diorite, basalt, diabase, and quartz-diorite. The interrelationships of these types of rocks, as well as their mineral composition, indicate a continuous magmatic differentiation of basic magma.

The presence of metals in the ambient air (ambient dust) in the urban environment is a frequent subject for research, and so far it has been worked out in many urban centers in the world. The systematic research for the contents of the ambient dust in the city of Skopje is not made before, so we cannot present such information. However, it should be emphasized that such information which refer on the contents of the urban dust exist in many towns, but that information is very changeable depending on the seasons in which the data is measured. As an example, on the basis of a large number of researches the metals which are present in the urban dust are divided in three groups: – Urban elements (Ba, Cd, Co, Cu, Mg, Pb, Sb, Ti, Zn). – Natural elements (Al, Ga, La, Mn, Na, Sr, Th, Y) – Elements with mixed background (Ca, Cs, Fe, Mo, Ni, Rb, Sr, U). There is accepted opinion that the background of the urban elements is primarily connected with the development of the traffic, the processes of corrosion of the materials build in the objects in the towns (buildings, houses, roads, etc.) as well as the emission of dust which appears in the soils, and fields with no grass. In order to be able to make any correlation of the obtained data which refer to a small number of measured samples (only of two locations) many deeper researchers are needed. From the other side, the influence of the contents of dust (as well as the ambient air) upon the health of the people is a topic which requests more serious and longer measures.

The paper presents the results of the latest tests of tailings from the old tailings in the Bor mine complex. A package of 31 elements was geochemically analyzed, in which with increased elemental contents are characterized the elements typical for the Bor ores such as copper (0.25–0.45% Cu), chromium (0.0047–0.1343% Cr), arsenic (0.0031–0.0127% As), selenium (0.30–4.77% Se), silver (0.15–2.87% Ag) and gold (0.08–0.65% Au). Miner- alogical study have shown the standardization of several minerals such as pyrite, bornite, chalcopyrite, magnetite and natural gold, which compositions have been confirmed by SEM–Scanning Electron Microscope. Quantitative mineral analysis gave the composition of the main constituents in the tailings dominated by quartz up to a maximum of 60.6%, amorphous mass up to 58.1%, ore minerals dominated by pyrite up to 20.4% followed by albite, microcline, hornblende and others.

In the geogenic Tl-extreme environments, such as Tl-rich sulphide deposits, secondary Tl-minerals play a crucial role in the mobility and fate of this toxic element. In the middle part of Allchar, there is a prevalence of Sb-mineralization accompanied with As, followed by minor Tl, Ba, Hg and Au. We used PXRD, SEM-EDS, Raman spectroscopy, pore-water analysis and chemical extractions to determine the distribution and speciation of Tl in the As- and Sb-rich waste dumps and soils (As: 3.8-17.7 g/kg; Sb: 0.9-16.4 g/kg and Tl: 127-837 mg/kg). Soil samples and waste dump material are composed mostly of dolomite, quartz, gypsum, pyrite, marcasite, stibnite, realgar and barite, followed by muscovite, kaolinite-group minerals and various Sb-oxides. Tl-sulfosalts fangite, Tl3AsS4, lorándite, TlAsS2 and pierrotite, Tl(Sb,As)10S12 are the primary Tl-sources and are mostly hosted in realgar. Tl dissolved during weathering under cicumneutral conditions is precipitated as As-beraing avicennite (0.55-6 at% of As), Tl2O3, crystallizing in massive aggregates up to 200 µm in length and tiny, fibrous Tl-bearing todorokite- or birnessite-type Mn-oxides (up to 8.5 at% of Tl) intregrown with avicennite and dolomite. Furthermore, sperulitic crystals of tiny (up to 3µm) Tl-Sb-oxides (Tl:Sb  3:1) (unknown mineral species) have been found intergrown with quartz, muscovite and minor dolomite. Thallium dissolved during weathering under acidic conditions (pH 2.8-3.1) didn’t precipitate at all. In these samples jarosite-group minerals, scorodite, tripuhyite and oxycalcioroméite have been formed. The pore water (pH: 2.8-7.8) contained large aqueous concentrations of Sb (up to 14 mg/l), As (up to 8.5 mg/l) and Tl (up to 464 µg/l). Mild extractions (ammonium nitrate and phosphate) mobilized up to xx% of the total Tl, xx% of the total Sb and xx% of the total As, indicating that large fraction of Tl is weakly bound and could be easily mobilized into the surrounding ecosystems. The identification of avicennite, Tl-Mn-oxides and Tl-Sb-oxides in near-neutral soils points to their stability at near-neutral soil pH and indicates their potential for the storage and preservation of toxic Tl in mine wastes and contaminated environments. Financial support of the Austrian Science Fund (FWF) (P 30900-N28) is gratefully acknowledged.

The mineralogical analysis of the samples from the Bor’s mine tailings, which were taken from boreholes, was realized in two stages. As a qualitative ore microscopic and quantitative X-ray structural analysis. About a dozen ore minerals, of higher intensity, were detected by ore microscopic analysis, such as chalcopyrite, magnetite, pyrite, bornite, molybdenite, native gold, etc. Quantitatively, with the help of the scanning-electron microscope, the compositions of all significant ore minerals were determined, from which it should be emphasized that in most of them there are no major deviations from the reference values. For chalcopyrite as the most intense mineral, the copper concentration ranged from 33.24 to 36.33% Cu, iron from 29.78 to 32.13% Fe and sulfur from 32.40 to 35.73% S, while in bornite those concentrations ranged from 61.99 to 64.01% Cu, from 11.40 to 13.01% Fe and from 23.69 to 25.43% S. The quantification of XRD confirmed the presence of pyrite, quartz, nacrite, alunite, anorthite, hornblende and others.

Five locations and five samples of materials from the phosphogypsum waste stack near Zgrpolci locality, in the vicinity of the city of Veles, were checked for their radon concentrations in air and phosphogypsum radon exhalation rate. The accumulation method using AlphaGUARD DF2000 device was used for specific exhalation rate determinations as well as for radon concentrations in air. The activity concentrations of 222Rn at 5 different sampling locations of the anthropogenically introduced phosphogypsym waste stack near the Zgrpolci locality ranged from 21.02 up to 142.20 Bq kg-3 . The 222Rn exhalation rates from these materials (from the same 5 locations) were in the range of 592.27-897.99 mBq m-2 h -1 . Key words: radon, air, phosphogypsum waste.